具有高界面压应力的高分子共混物Ⅰ.制备和拉伸性能

考察了高界面压应力对不相容聚对苯二甲酸乙二醇酯(PET)/聚乙烯(PE)和聚碳酸酯(PC)/PE共混物拉伸性能的影响.高界面压应力是共混物低温成型(PE的成型温度)时,分散相与基体从加工温度冷却到室温过程中基体的收缩比分散相粒子大产生的.尽管PET/PE和PC/PE共混物极不相容,但拉伸强度和模量随着PET和PC含量增加而增加.PET与PC含量相同时,PC/PE的拉伸强度和模量高于PET/PE的.采用Takayanangi方程计算共混物的拉伸模量时,具有高界面压应力的PC/PE共混物的拉伸强度高于界面有良好粘结的共混物的理论值,表明在不添加增容剂时,可通过控制加工条件改善共混物界面相互作用,提高共混材料的性能.

Polymer blends with high interfacial compressive stress: preparation and tensile properties

The immiscible poly(ethylene terephthalate) (PET)/polyethylene (PE) and polycar-bonate (PC)/PE blends were examined to study the influence of high interfacial contact (pseudo-adhesion) on the tensile mechanical properties. The high interfacial contact originated from the differ-ence in thermal contraction of the two polymers during cooling from the low processing temperature to room temperature. As a result of the pseudo-adhesion, the tensile strength and modulus of the PET/PE and PC/PE blends increase steadily with increasing PET and PC content. However, the increased values of the PC/PE blend are higher than those of the PET/PE blend at the same PET and PC concentration. The experimental values of the tensile strength for PC/PE blend are higher than those obtained from Takayanagi equation which is suitable for the blends with good interfacial adhesion. This indicates that in the absence of a compatibilizer, the interfacial interactions between thematrix and the dispersed phase can be improved by controlling the processing parameters, thus giving rise to the mechanical properties of the blending materials.